A knife of this type is well known based on public prior use as disclosed by the applicant. The knife has a housing that together with a handle forms a pivot joint. The handle can be moved relative to the housing between a starting position and an active position. The knife furthermore has a blade support movable between a safety position and a cutting position. When in the cutting position, the blade projects from an opening of the housing and cutting can be done. In the safety position, the blade is inaccessible to the user. When the handle is in the starting position, the blade is in the safety position. When the handle is moved to the active position, the blade support moves to the cutting position. Relative movement of the handle and the housing enables the handle to be removed from the housing and provides access to the blade support allowing the blade to be replaced.
The blade has a safety device comprising a first latch that can prevent movement by the handle between the starting position and the active position. The safety device furthermore has a second latch that prevents removal of the housing from the handle, and thus unintended access to the blade, in the safety position.